Packages of the above kind are for example known from U.S. Pat. No. 3,550,836 wherein an egg package is disclosed, which comprises a bottom part formed from a fibrous material, the bottom part comprising a rear side, a front side, two end sides, and a plurality of egg-receiving compartments having non-planar side surfaces so as to match at least partially the outer contours of an egg, the plurality of compartments being arranged in at least two parallel rows with upwardly extending projections located between the rows of compartments.
Said egg package further comprises a cover part comprising two substantially planar end surfaces, substantially planar rear and front surfaces, and a substantially planar top surface, said cover part being formed by chipboard and being connected to the bottom part via an elongated flap extending from the rear part of the bottom part, said elongated flap being provided with a hinge in the transition between said elongated flap and the rear part of the bottom part so as to allow the cover part to move between an open position and a closed position, said elongated flap at least in part overlapping the inner side of said rear surface of the cover part.
The bottom part further comprises a retainment flap hinged to the front side of the bottom part, said retainment flap comprising at least one outwardly extending retainment projection for locking engagement with two co-operating apertures in the front surface of the cover part.
Mostly, the bottom part and cover part are being constructed in such a way that the inner and outer surfaces of the bottom part as well as the inner surfaces and outer surfaces of the cover part are complementary, so that when the egg package is fully open, it may be nested with other, identical egg packages for shipment and/or storage. Usually, the egg packages are formed in such a way that one fully open egg package fits within the egg package immediately preceding it in a stack. This kind of stacking of egg packages is a very compact way of stacking egg packages together, and this way of stacking egg packages together is usually referred to as nesting.
Molded pulp is desirable for production of an egg package because it can be shaped to conform to a desired degree to the configuration of the eggs, and also at the same time it has the adequate softness to constitute appropriate cushioning support for the eggs and to offer desired shock resistance. However, while the rough and fuzzy surface of the moulded pulp normally used for egg cartons is partly responsible for this beneficial cushioning effect, this same rough and fuzzy surface is not receptive for lithographic decoration of multiple colours or other printing.
Additionally, moulded pulp has an inherent softness in the material, which therefore may lead to inadequate support of the eggs during transport, by handling in packaging machinery, and by manual handling in for example a supermarket. However, although the egg package disclosed in the above-mentioned US patent has a cover made of chipboard, which inherently is stiffer than moulded pulp, its construction is of such a form that it does not provides an adequate stiffening support for the bottom part of the egg package.
In addition to egg packages formed of a fibrous material, such as pulp, several attempts to manufacture egg packages from plastic have been proposed. For example in EP 2 301 359 is disclosed an egg package made from plastic.